The present invention relates to improvements in apparatus for applying adhesive substances to blanks which are to be converted into packets, cartons or other types of receptacles, e.g., into packets which contain arrays of rod-shaped smokers"" products or into so-called cartons which contain arrays of cigarette packets or the like. The invention also relates to improvements in the configuration, mounting and utilization of certain component parts, such as back supports or others, of adhesive applying apparatus (often called pasters) which can be utilized in connection with the making of various types of receptacles for arrays or other groupings of discrete commodities.
It is customary to advance various types of discrete blanks and/or continuous or elongated sheets, strips or webs of wrapping material past one or more devices which are designed to apply a suitable adhesive paste to selected portions of such discrete or continuous blanks prior to causing the adhesive-coated portion or portions of a blank to adhere to different portion or portions of the same blank or to one or more different blanks. For example, the flaps and/or tucks at the sides and/or at the top or bottom ends of partially completed cigarette packets must be coated with adhesive and thereupon folded to abut against and to adhere to the adjacent walls, panels, flaps or other parts of the same blank(s) or to portions of different blanks.
A modern paster, e.g., an adhesive applicator which is utilized in a high-speed packing machine for arrays of cigarettes or in a cartoning machine for cigarette packs, normally employs one or more nozzles which discharge a hot melt, a cold melt or another suitable paste in the form of a film, a stream or a strip upon a continuous web or upon selected portions of successive blanks of a series of discrete blanks. The nozzles can be designed to come into actual contact with the running blank or blanks, or of the type which merely discharge adhesive but do not actually engage the running blank or blanks. A presently utilized nozzle (distributed by the German Firm VALCO) is fixedly mounted adjacent the path for the advancement of blanks, and a suitable conveyor system is employed to transport the blanks past the orifice or orifices of the fixed nozzle.
The quality, as well as the appearance (and hence the sales appeal) of a cigarette packet or another container for cigarettes or other smokers"" products, depend to a large extent upon the stability of such packs, and this also holds true for the quality and appearance of the aforementioned cartons which are often designed to contain arrays of ten packs, e.g., two superimposed layers each of which contains a row of five neighboring packs. Therefore, satisfactory application of requisite quantities of an acceptable adhesive is of great importance; moreover, the adhesive should be prevented from adhering to parts of a packing machine because any interruptions of operation of such machines, even for short or very short intervals of time (e.g., to clean the machine and to thus prevent patches of adhesive from attracting dust and/or blanks or fragments of wrapping material on their way toward, past and beyond the wrapping station) entail huge losses in output of a modern packing or cartoning machine. Such satisfactory application of adhesive can be ensured by setting up a packing machine in such a way that the area of contact between the orifice of the nozzle of an adhesive applicator and successive blanks is imparted an optimum shape, that the cross-sectional area(s) of the adhesive-discharging orifice(s) in the nozzle matches or match an optimum shape and/or that the blanks are compelled to advance along a predetermined path without any or with negligible stray movements.
It has been found that the establishment of optimum contact between the nozzle of an adhesive applicator and the selected portion or portions of each of a short or long series of successive (coherent or discrete) blanks of wrapping material is one of the critical prerequisites for the making of optically, mechanically and/or otherwise acceptable cigarette packs or other types of smokers"" products. The establishment of an optimum contact necessitates the placing of selected portions of each of a series of blanks into surface-to-surface contact with one or more predetermined portions of the surface of a paster.
Published German patent application Serial No. 1 511 044 discloses a paster which employs a metallic leaf spring serving to ensure the establishment of predictable contact between a continuous blank or successive blanks and the nozzle of the paster. The leaf spring is tiltable relative to the nozzle to thus urge the running blank or blanks against the nozzle. A drawback of such proposal is that the leaf spring or springs is or are apt to be moved out of requisite position(s), damaged or deformed during frequent cleaning, maintenance and/or alignment work. This often results in contamination of the external surfaces of the nozzles and/or of other parts of the paster with adhesive paste, in the application of adhesive to the external surfaces of the packs and/or cartons, as well as in the application of adhesive to the external surfaces of machine parts located downstream of the adhesive applicator(s). The misapplied adhesive is likely to be part of adhesive which was intended to be applied to packs, cartons and/or other receptacles the parts of which should be held together by adhesive, i.e., the misapplication of adhesive results or is likely to result in the making of weaker adhesive bonds or in the absence of adhesive bonds because the adhesive was misapplied during intended application to blanks and/or during subsequent processing.
U.S. Pat. No. 5,732,533 (granted Mar. 31, 1988 to Focke et al. for xe2x80x9cPROCESS AND APPARATUS FOR PRODUCING PACKS WITH AN OUTER WRAPPER CONSISTING OF PAPER OR THE LIKExe2x80x9d) discloses the application of glue patterns to blanks of wrapping material, subsequent deactivation of applied glue, and reactivation of deactivated glue upon completed conversion of blanks into containers for cigarettes and the like. A drawback of such proposal is that the patented machine takes up substantial amounts of space as well as that the additional equipment for the application of adhesive at a location remote from the actual wrapping station, for the setting of adhesive prior to transport of adhesive bearing blanks to the wrapping station, and for reactivation of adhesive at the wrapping station contributes significantly to the cost of the packing machine and to its proneness to malfunctioning. The patentees further propose to press the flaps, closure tabs and like parts of the blanks against each other during the last stage of the wrapping operation, i.e., at a location which is remote from the paster or pasters.
An object of the invention is to provide a novel and improved apparatus for the application of adhesive to a continuous blank or to a series of successive blanks in such a way that the shapes and/or the quantities of applied adhesive match or closely approximate the required or desired optimum shapes and/or quantities.
Another object of the present invention is to provide novel and improved parts or groups of parts for use in an apparatus of the above outlined character.
A further object of the instant invention is to provide the apparatus with novel and improved means for reducing the percentage of wasted adhesive in a machine for the making of packets, packs, cartons and/or other types of receptacles for smokers"" products.
An additional important object of this invention is to provide a novel and improved mounting for the nozzle or nozzles in an adhesive applicator of the above outlined character.
Still another object of the invention is to provide an apparatus which is constructed and assembled in such a way that it can automatically compensate for wear upon several of its parts and which can be put to use in existing cigarette packing, cartoning and/or other types of machines for confinement of smokers"" products.
A further object of the invention is to provide a novel and improved method of at least partially automatically compensating for wear upon various parts of adhesive applying devices, especially but not exclusively in devices which can be utilized for the application of adhesive to various parts of wrappers for smokers"" products.
Another object of the present invention is to provide a novel and improved method of enhancing the quality of packets, packs cartons and/or analogous containers wherein flaps, panels, walls, tucks and like parts are held together by an adhesive, to reduce the cost of making such containers, and to reduce the numbers of rejects in packing machines for cigarettes and the like.
One feature of the present invention resides in the provision of a device for urging an at least substantially sheet-like or panel-like advancing blank sideways against an adhesive dispensing implement, such as a paster of the type employed in a cigarette or carton packing machine. The improved device comprises a back support having a surface which is arranged to contact one side of an advancing blank while another side of the blank abuts the implement, and at least one bearing which mounts the back support with freedoms of movement in a plurality of directions relative to the implement.
It is often preferred and advisable to mount the back support with freedoms of movement in three different directions relative to the implement, e.g., in the directions of the three cartesian coordinates which are normal to each other.
The at least one bearing can define at least one pivot axis for the back support, and one of the freedoms then includes or can include pivotability of the back support about the at least one pivot axis. Another of these freedoms can include movability of the back support transversely of the aforementioned axis; such movements of the back support take place, or can take place, while the blank advances in a predetermined direction.
The improved device can further comprise means for yieldably biasing the back support to a predetermined position relative to the at least one bearing. Such biasing means can comprise at least one spring, e.g., at least one coil spring which reacts against the at least one bearing and bears upon the back support.
At least a portion of the aforementioned surface of the back support can have a concave shape or a convex shape.
It is also possible to employ a back support which resembles and acts as a cradle in that it is rockable relative to the at least one bearing.
Still further, it is possible to employ a spherical (universal) joint which acts between the back support and the at least one bearing.
Another feature of this invention resides in the provision of an apparatus which serves to apply an adhesive to substantially sheet- or panel-like blanks. The apparatus comprises means for advancing a series of successive blanks along a predetermined path, an adhesive applicator having a surface which contacts one side of each of the series of successive blanks in a predetermined portion of the path, a back support which contacts another side of each of the series of successive blanks in the predetermined portion of the path, and at least one bearing mounting the back support and/or the applicator with freedom of movement in at least one direction relative to the applicator and/or the back support.
The at least one bearing can include means for mounting at least a portion of the applicator with at least one freedom of movement relative to the other of the back support and the applicator. Such portion of the applicator has two or three freedoms of movement relative to the back support, and such apparatus can further comprise means for yieldably biasing the portion of the applicator to a predetermined position relative to the back support. At least one of the aforementioned two or three freedoms of movement can include the ability of the aforementioned portion of the applicator to pivot about a predetermined axis, and the advancing means of such apparatus can include means for moving successive blanks of the series in a predetermined direction; at least one of the two or three freedoms of movement can include linear movability of the aforementioned portion of the applicator at least substantially transversely of the predetermined direction. Another of these freedoms of movement can include the ability of the aforementioned portion of the applicator to pivot about a predetermined axis. Still further, such apparatus can comprise at least one resilient element which reacts against the at least one bearing and bears upon the aforementioned portion of the applicator to yieldably urge the applicator portion to a predetermined position relative to the back support.
The applicator of the improved apparatus can comprise at least one resilient component, and such applicator can form part of a wrapping machine for smokers"" products.
The novel features which are considered as characteristic of the invention are set forth in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling, installing and operating the same, together with numerous additional impartant and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawings.